1. Field of the Invention
The present invention relates to a solid-state imaging device, an imaging device, and a semiconductor device.
2. Background Art
In various electronic devices and semiconductor devices such as image processing devices, imaging devices, and solid-state imaging devices, an output circuit that selects one of the respective signals of plural routes and sequentially transfers and outputs signals to a downstream circuit via one route of output lines may be used.
For example, a physical quantity distribution sensing semiconductor device formed by arranging unit component elements (e.g., pixels) having sensitivity to externally input electromagnetic wave such as light or radiation linearly or in a matrix are used in various fields.
For instance, in the field of video devices, solid-state imaging devices of CCD (Charge Coupled Device) type, MOS (Metal Oxide Semiconductor) or CMOS (Complementary Metal-oxide Semiconductor)-type for sensing light (an example of electromagnetic wave) of physical quantities are used. These devices read out the physical quantity distribution converted into electric signals by the unit component elements (pixels in the solid-state imaging devices) as electric signals. The MOS-type and the CMOS-type are representatively described by the CMOS-type as below.
Further, among the solid-state imaging devices, there is an amplification solid-state imaging device including pixels having an active pixel sensor (APS, also called a gain cell) configuration with drive transistors for amplification in pixel signal generating units that generate pixel signals according to signal charge generated in charge generating units. For example, many of the CMOS-type solid-state imaging devices have such a configuration.
For example, a CCD-type solid-state imaging device is proposed in JP-A-2002-165134, and a CMOS-type solid-state imaging device is proposed in JP-A-2005-278135. In JP-A-2005-278135, a configuration including column parallel ADC formed by providing analog-digital converters (hereinafter, abbreviated as ADC) with respect to each column in the matrix arrangement of unit pixels is shown.
In order to externally output the pixel signals acquired by the solid-state imaging device, an output circuit that transfers and outputs signals of the respective pixels (pixel signals and pixel data) forming imaging signals (imaging data in digital cases) is mounted on the solid-state imaging device as an interface circuit to an external circuit.
Recently, with higher definition of shot images, the number of pixels and the drive frequency have tended to increase and the transfer speed in the output circuit have become higher, and accordingly, power consumption in the output circuit has become problematic and measures therefor has been demanded.
For example, in JP-A-2002-165134, a mechanism in which a switching unit that turns on/off power supply to an output circuit and a switching control unit that supplies a control signal to the switching unit and controls the switching unit to turn off the power supply to the output circuit in a blanking period is proposed.